This invention relates to a device for protecting a sensor in the exhaust system of a vehicle and more particularly to a device for protecting an oxygen sensor of a motorcycle.
In order to improve the performance of internal combustion engines, it has been proposed to control the engine through one or more sensors that are positioned in the exhaust system of the engine. For example, it has been proposed to employ an oxygen sensor for sensing the amount of oxygen in the exhaust gases to determine the air/fuel ratio for the engine. The induction and charge forming system is then adjusted in response to the output of the oxygen sensor so as to maintain the desired fuel/air ratio under all running conditions.
In order to ensure good accuracy of the exhaust sensors, it is desirable to position them as close as possible to the cylinder. However, where multiple cylinders are employed, there is some advantage in placing the oxygen sensor in a common portion of the exhaust system, such as the exhaust silencer or muffler, so that the effect of cylinder to cylinder variations can be minimized. Although such arrangements are highly desirable, they provide certain problems in connection with the application to certain types of vehicles.
For example, in a motorcycle, it is the typical practice to have the running components such as the engine and portions of the exhaust system generally exposed. In addition, a common type of motorcycle layout places the engine in a transverse position in the motorcycle and the exhaust pipes extend from forwardly facing exhaust ports downwardly and then beneath the oil pan of the engine where the exhaust muffler is positioned. With such an arrangement, the sensor positioned in the muffler is exposed and can be easily damaged by foreign objects thrown up by the wheels of the motorcycle.
It is, therefore, a principal object of this invention to provide an improved exhaust sensor layout for a motorcycle.
It is a further object of this invention to provide an exhaust sensor layout for a motorcycle in which the exhaust sensor is well protected from foreign materials.
It is a further object of this invention to provide an improved exhaust sensor layout for a motorcycle wherein the exhaust sensor is well protected but wherein a flow of air may be permitted across the sensor for cooling purposes without permitting the sensor to be struck by foreign objects contained within the air stream.